SAULT STE. MARIE -- The Great Lakes maritime community is now pushing for a new lock in Sault Ste. Marie.

Shippers in Duluth, Minnesota and elsewhere say a new Soo Lock would ensure free flow of large ships between Lake Superior and the lower Great Lakes, especially if something happened to the existing lock causing it to be taken out of service.

A new Soo Lock also brings the possibility of year-round operations on the Great Lakes.

Officials estimate building costs to be around $475 million.

Congress first authorized the project two decades ago, but never came up with the money to build it.